This study was conducted over two growing seasons (2022-2023 and 2023-2024). Using a randomised block design, 16 treatments consisted of combinations of vermicompost, biochar, jaggery, poultry manure, farmyard manure, cow urine, and neem cake, and three replications were used in the study. The objective was to assess how these organic amendments affected the antioxidant, phenolic and flavonoid contents in guava fruit. The treatment T6(Vermicompost 5 kg/tree + Biochar 7.5 kg/tree + Jaggery 1.25 kg/tree) produced the highest levels of antioxidant, phenolic and flavonoid, according to the results. T6 in particular showed an increase in antioxidant activity from 46.48% to 48.14%, phenolic content from 29.72 mg TA/g to 30.93 mg TA/g and flavonoid content from 23.88 mg/g FW to 25.14 mg/g FW. This study provides important information for sustainable horticultural practices by highlighting the potential of organic amendments to enhance the nutritional qualities of guava cv. L-49.
